Tripping mechanism



W. A. ATWOOD.

TRIPPING MECHANISM.

APPLlCATlON FILED Nov. 21. ms.

1,33 1,086, Patehted Feb. 17,1920.

Figl.

Inventar:

Winfield A. Atwood, b5 flW/q. 48%

Hisoqttornes.

UNITE ANT FFIQE.

WIN FIELD A. ATV/00D, OF SGHENECIADY, NElIV YORK, ASSIGNOR T0 GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

TRIPPING MECHANISM.

Application filed November 27, 1916.

T 0 all whom it may concern Be it known that I, W'INFIELD A. ATwooD, a citizen of the United States, residing at Schenectady, in the county of Schenectady, State of New York, have invented certain new and useful Improvements in Tripping Mechanisms, of which the following is a specification.

My invention relates to circuit controlling devices and especially to tripping mechanisms for automatically opening such devices.

The object of my invention is to generally improve the tripping mechanism for circuit controlling devices, and more particularly to provide a novel and improved means for resetting such mechanisms and for adjusting the tripping point thereof.

My invention is of general application but is especially applicable to circuit controlling devices, such as circuit breakers and switchesprovided with automatic tripping mechanisms such, for example, as shown by the structures of the U. S. patents to Edward M. Hewlett et aL, 1,011,784, and to Charles H. Hill, 861,212. When such circuit breakers are mounted near the top of a switchboard or panel, the resetting of the tripping mechanism has been rendered awkward and difficult to accomplish, due to the fact that the mechanisms must be reset by pushing down the solenoid plunger from the top, a separate means being provided for regulating the tripping point of the mechanisms from below. In the novel mechanism of my invention, I overcome these disadvantages by providing a tripping mechanism including a common means for resetting the mechanism and for regulating its tripping point, which means is conveniently located and operable in one direction for resetting the mechanism, and in another direction to regulate the tripping point thereof. I also provide means for locking the resetting means against movement in trip adjusting direction and for automatically returning the resetting means from resetting position to its initial position.

The novel features which I believe to be characteristic of my invention will be definitely indicated, in the claims appended thereto; the features of construction and mode of operation will be best understood by reference to the following description Specification of Letters Patent.

Patented Feb. 17, 1920.

Serial No. 133,836.

taken in connection with the accompanying drawing which shows the preferred embodiments of my invention and in which Figure 1 is a view, partly in section, of one type of tripping mechanism for a circuit breaker, embodying the novel features of my invention; Fig. 2 is a view, partly in section, of a portion of another type of tripping mechanism embodying the features of my invention, Fig. 3 is a diagrammatic illustration of the connections for the tripping mechanism shown in Fig. 1, and Fig. 4c shows in an exploded view, a detail of the mechanism shown in Fig. 1.

I have shown in Fig. 1 a tripping mechanism adapted to open a circuit breaker of the type shown in U. S. patent to Edward H. Hewlett ct aZ., 1,011,784, in response to conditions of reverse current. This mechanism comprises a control means consisting of two actuating windings or coils 1 and 2 connected as best shown in Fig. 3. Coil 1 is a potential or polarizing coil, better known in the art as a flash coil, and coil 2 is current coil shown connected in series with the circuit through the circuit breaker 3. The two coils have a common magnetic circuit comprising a magnet frame 4 with a pole piece 5 threaded therein and held in place by a lock nut 6 and a common arma ture or movable core 7 Extending freely through the pole piece 5 and core 7 and movable relatively thereto, is a brass operating rod or resetting means 8 having an upper cylindrical portion and a lower plural sided portion 9, shown by wayof example,

as a squared or four sided portion, the rod being mounted for either longitudinal or rotary movement by the handle member 10. The resetting member or operating rod 8 extends beyond the core 7 and carries secured at its upper end, a member or ca'p piece 11 which carries loosely mounted cap piece 11 or biased to contact opening;

position and for holding the cap piece 11 biased t normal position, I provide the.

springs 15 and 16 respectively, Thespring 16 is a means for returning the resetting member 8 to its initial position from resetting position as will be described later.

Upon an extension of pole piece 5 below the magnet frame 1 is secured a tubular casing or calibrating tube 17 of non-magnetic material through which the rod or resetting member 8 passes. Slidably mounted on the rod 8 for longitudinal movement within the tube 17 and adjacent the pole piece 5 is the tripping member of the tripping mechanism comprising tripping arms 18 extending outside the tube 17 through transverse openings or slots 19 and adapted to engage the latching member of the circuit breaker mechanism to release the same and cause an auto matic opening of the circuit breaker as will be presently described. The tripping arms 18 are integrally related to a cylindrical portion 20 carried by a member 21 having an upwardly extending tubular or core engaging portion 22 of brass slidably movable on the resetting member 8 and extending beyond the top of the pole piece 5 to engage the core 7 and to provide, under circuit opening conditions, an air gap between the plunger and the pole piece. The resetting mem ber 8 extends freely through the tubular portion 22 and through an opening in the cylindrical portion 20 to lock this portion in engagement with member 21. The tripping member 21 carrying the tripping arms 18 and tubular portion 22 is biased to tripping position by a biasing or actuating means comprising a spring 23 surrounding the rod 8 and supported at its upper end by an extension on member 21 and carried at its lower end by a member 24: freely movable on the portion 9 of the rod 8 and supported on a calibrating or adjusting member 25 threaded to the interior of the tube 17 and rotatably movable for lon itudinal adjustment. The calibrating mem er 25 is provided with a square opening through which the square portion 9 of rod 8 passes and by means of which the member 25 is keyed to the resetting member in response to rotary movement thereof.

When the resetting member 8 is longitudinally operated or pulled down by its handle 10 into resetting position, the core 7 is moved down by its engagement with cap piece 11 until it engages the pole piece 5 moving at the same time, through the portion 22, the member 21 and tripping arms 18 into non-tripping or resetting position and compressing spring 23. On releasing the resetting member 8, it returns to its initial position under the compression of spring 16 but the core 7 is held or restrained in its position by electromagnetic action against the tension exerted by spring 23 as will be described more in detail hereinafter. By rotation of the rod or resetting member 8 by its handle 10, the square portion 9 acts to raise or lower the calibrating member 25 and hence increase or decrease the tension exerted by the spring 23 on the actuating member 11. By varying the tension exerted by the spring 23, the force tending to raise the core 7 against its magnetic pull is varied and hence a means provided for adjusting the tripping point of the mechanism. The position of the calibrating member 25 within the tube corresponding to various current tripping values is noted through a slotted opening in the tube 17, not shown.

For locking the current adjusting means in position and preventing it from moving in response to longitudinal movement of the resetting member 8, a locking means is provided to prevent rotary movement of the resetting member until adjustments in current setting is desired. This locking means comprises a member 26 threaded in the end of tube 17 and slidably movable on the portion 9 of rod 8. The member 26 is provided with two oppositely arranged slots adapted to register with corresponding slots in the end of tube 17 and into each registering pair of slots extends a lug carried on a washer 27 at the end of the tube. This washer and its lugs are adapted to prevent rotation of the member 26 and to lock it to the tube 17. Extending freely through the opening in the member 26 and washer 27 but keyed to the plural sided portion 9 of the rod 8 is a threaded member or bolt 28 provided with a flange which is adapted to engage the member 26. Threaded upon the bolt 28 is a collar 29 inclosing the end of tube 17 which is adapted when screwed up tightly against the end of tube 17 to hold the flange of bolt 28 in firm en agement with member 26 which in turn is locked to the tube 17 through washer 27. In this way the bolt is held locked and being keyed to the portion 9 of rod 8 consequently holds the resetting member locked from rotary movement. When the locking means is in locking position, the resetting member is movable longitudinally into and out of resetting posi tion but is lockeo against rotary movement hence holding the current adjusting means locked in position. To limit the movement of collar 29 inreleasing position a lock nut go is threaded on the bolt 28 below the col- The operation of my tripping mechanism and in so moving the member 11 engages the core 7 and carries it down until it engages the pole piece 5 closing its air gap and compressing spring 16. The member 11 at the same time compresses spring 15 and carries contact plate 13 into engagement with contacts 1 1 and thereby closes a circuit, as shown in Fig. 3, across the machine 31 to energize coil 1. The current through coil 1 sets up a flux in the magnet frame 4 magnetizing it or polarizing it in a definite direction in response to the potential of the circuit. The movement of the core downward carries the tripping member 21 with tripping arms 18 downward by means of the core engaging portion 22, moving the tripping arms out of the path of the latching member of the circuit breaker mechanism into resetting position and at the same time compressing the spring 23 to bias the tripping member to tripping position.

After longitudinally moving the resetting member 8 into resetting position and pulling the core 7 down against the pole piece 5, the handle 10 is released and under the action of the spring 16, the operating rod returns freely to initial or normal position independent of the core 7, and tripping member 21, and at the same time opens thecontacts 13 and 1a to deenergize coil 1. The core 7 is however, held down against the pole piece 5 by the action of the polarized magnet frame 1 thus providing an electromagnet restraining means for holding the tripping member in resetting position.

The circuit breaker 3 can. now be closed in the ordinary manner and the latching member thereof moved to latching position. Upon closing the circuit breaker 3, the coil 2 being in series, is energized and produces a flux under normal conditions in the same direction as the polarized magnet frame 4L which acts to aid in maintaining the core 7 in restraining position and the tripping member in resetting position. Upon a reversal of current, however, the flux set up by the coil 2 opposes the magnetism of the magnet frame and when the pull exerted by the magnetic action is reduced to an amount insufficient to oppose the action of the spring 23, the core 7 is forced up and with it the tripping member 21 until the arms. 18 engage the latching member of the circuit breaker and cause it to open.

Under normal condition the locking means for the tripping mechanism is in locking position, that is, the collar 29 is screwed tightly against the end of the tube 17 holding the flange of the bolt 28 firmly in engagement with the member 26 so that the rod or resetting member 8 is locked from rotary movement but can be moved longitudinally into and out of resetting position. When it is desired to change the current setting or the tripping point of the tripping mechanism, the collar 29 is unscrewed suiiiciently to allow a freedom of movement between the bolt 28 and the member 26. Hence by rotating the resetting member 8, the calibrat ing member 25 is moved up or down the calibrating tube to vary the tension on spring 23 to that corresponding to the current value desired.

InFig. 2 I have shown the novel features of my invention embodied in a tripping mechanism operative to trip a circuit breaker in response to underload. The resetting means and locking means is the same as that for the reverse current type of tripping mechanism shown in Fig. 1 and for that reason has not been shown. The only features of difference being those inherent to an underload type of device and for this reason the contact plate 13, contacts 14 and spring 15 are omitted as is also the coil 1. When the resetting member 8 is moved to resetting position it merely moves the core 7 into en agement with the pole piece 5 or into holding position and by closing the circuit breaker, the series underload coil 32 is energized and acts to hold the core down or restrained while the resetting member returns, as before, to its initial position. The tripping member 21 is held down or restrained as before against the action of its spring 23 until the current through the coil 32 or the load, falls to an amount insufficient to restrain the core 7 when it is carried upward by the movement of the tripping member to tripping position. In a similar manner the current setting of tripping mechanism can be adjusted by the resetting member 8.

My invention may be embodied in other forms than that shown and described and I, therefore, do not wish to be restricted to the precise construction shown but intend to cover by the appended claims all. changes and modifications which are within the scope of my invention and will be apparent to those skilled in the art.

What I claim as new and desire to secure by Letters Patent. of the United States, is

1. A tripping mechanism comprising a tripping member, means for moving said member to tripping position in response to predetermined abnormal conditions, means for regulating the tripping point of said moving means, and a common means operative to reset said tripping member and to control said regulating means.

2. A tripping mechanism comprising a tripping member, means for moving said member to tripping position in response to predetermined abnormal conditions, means for regulating the tripping point of said moving means, and an operating rod operatively related to said tripping member to reset said member in response to longitudinal movement of said rod and to con- Ill trol said regulating means in response to rotary movement thereof.

,3. A tripping mechanism comprising a tripping member, means for moving said member to tripping position in response to predetermined abnorn'ial conditions, means.

for re ulating the tripping point of said moving means, a common means oierative in one direction to reset said tripping member and in another direction to control said regulating means, and means for locking said common means against movement in the direction to control said regulating means.

4. In a device of the character described, a tripping member restrained in resetting position and biased to tripping position, biasing means adjustable to vary the tripping point of said member, and an operating rod longitudinally movable to carry said tripping member into resetting position and rotatably movable to adjust said biasing means.

5. In a device of the character described, a tripping member restrained in resetting position and biased to tripping position, biasing means adjustable to vary the trip ping point of said member, an operating rod longitudinally movable to carry said trip ping member into resetting position and rotatably movable to adjust said biasing means, and means for operating said rod from the lower end thereof.

6. In a device of the character described, a tripping member restrained in resetting position and biased to tripping position, biasing means adjustable to vary the tripping point of said member, an operating rod longitudinally movable to carry said tripping member into resetting position and rotatably movable to adjust said biasing means, and means for locking said operating rod against rotation.

7. In a device of the character described, a tripping member biased to tripping posi tion but adapted to be held in resetting position, means for holding said member in resetting position until the occurrence of a predetermined condition, actuating means adjustable to move said tripping member into tripping position When said predetermined conditions occur, adjusting means for said actuating means, and a member longitudinally movable to reset said tripping member and rotatably movable to control said adjusting means.

8. In a device of the character described, a solenoid, a magnetic member for said solenoid 'movable into holding position, a tripping member biased to tripping position but restrained in resetting position by said magnetic member in holding position, actuating means adjustable to vary the force tending to overcome said magnetic member and move said tripping member into tripping position, operating means rotatably movable to control said actuating means and longitudinally movable to move said core to holding position, and means for locking said operating means against rotative movement.

9. The combination with a solenoid and its core, of a calibrating tube, a tripping member longitudinally movable in said tube and having a portion cooperating with said core, a spring Within said tube for actuating said tripping member, a calibrating member supporting said spring and rotatably mounted Within said tube to vary the force exerted by said spring, and a rod extending through said tube and said solenoid adapted to position said calibrating member in response to rotary movement thereof and to cause said core to move said tripping member to resetting position in response to longi tudinal movement thereof, and a handle at the lower end of said rod for operating the same.

In Witness whereof, I have hereunto set my hand this th day o1 November, 1916.

WINFIELD A. ATl/VOOD. 

